This invention relates to an ostomy coupling.
Ostomy couplings are used to connect and disconnect a bag for receiving a stomal discharge to and from a medical grade adhesive pad which is applied to the peristomal area of the skin of the wearer. Many designs of ostomy coupling are known. One which has enjoyed considerable commercial success is described and claimed in U.K. Patent No. 1,571,657.
An ostomy coupling in which unlocking of two coupling parts is achieved by deforming a ring in the form of a closed loop is disclosed in our U.K. Patent Application No. 9409037.0, filed May 6, 1994.
It has been proposed by Kubo, in Japanese Utility Model No. 62-11610, published February 1985, that an ostomy device should have a double female ring structure which can interengage with a male ring. The male ring may be on the bag and the female ring on a skin-attachable adhesive pad, or vice-versa. The outer ring on the female ring is circular and flexible and has a pair of inwardly-extending catches at opposite ends of a diameter. By pressing on two diametrically extending lugs, whose diameter is substantially at right angles to the diameter joining the catches, the outer female ring is deformed so that the catches are caused to move radially outwardly, so permitting separation of the two coupling parts.
This arrangement, though perhaps operable in theory, has serious disadvantages in practice, for example (i) to connect or disconnect it is necessary to hold the coupling at four places, approximately spaced at 90.degree. intervals around the periphery, (ii) pressing on two diametrically opposed regions will tend to bend the coupling out of its normal plane and the forces applied may easily cause the body side pad to be partially (or wholly) detached from the skin of the wearer, also the need to press in both ends of the diameter fully, and simultaneously, means that releasing the bag-side coupling is subject to uncertainty, (iii) the repeated attachment and withdrawal of the bag-side coupling part will cause the o-ring (provided to prevent escape of excreted matter between the male and female rings) to become worn, so compromising its sealing qualities with potentially highly embarrassing and undesirable results, (iv) the wearer may find it difficult to determine whether or not the two coupling parts are properly engaged, (v) the accuracy and forces needed for manipulation to connect or disconnect will be well beyond the capability of an infirm, confused, elderly or impatient wearer; (vi) it is hard to be sure that the appliance is properly locked; and (vii) in the case of large sizes, the old and infirm will find it physically difficult to span with their hand and push in diametrally opposed regions of the ring.
In U.S. Pat. No. 5,180,377 there is disclosed an ostomy coupling in which a bag-side coupling attached to an ostomy pouch can be held onto to a body-side member by a third member which is substantially circular, deformable, and clamps or grips the bag side coupling when it is tightened. In practice, the diameter of the third member is reduced by operation of a mechanical control mechanism, some of whose parts are attached to the third member. While it may be true, as the patentee states, that a sealed mechanical connection of bag- and body-side couplings can be achieved using such a mechanism, the overall construction is relatively complex, which of course affects manufacturing costs.
PCT published Applications Nos. WO91/01118 and WO91/01119 relate to an ostomy coupling and to a ring for locking such a coupling. The ring has two free ends which are manually pulled together to tighten the ring circumferentially around bag- and body-side coupling parts whose structure is designed in various ways so that they can inter-engage. This results in a variety of relatively complex designs, likely to be costly to manufacture. Manipulation of such a coupling will potentially give rise to difficulties for infirm, elderly, or non-dexterous persons.
It is an aim of this invention to provide improved designs of ostomy couplings which embody a springy or resilient split ring as a locking ring. That is, the ring is generally circular in form but has a single gap therein, subtending a small angle, e.g. 5 to 15.degree..